Angle is a significant unit of measurement, which makes the measuring of angle an important part of measurement. With the unceasing development of productivity and science, the measurement of angle, of which the technology level and precision are improved ceaselessly, is more and more applied in the field of industy, scientific research and so on. In the field of angle measurement, optic method is characterized by high precision and noncontact measuring, which makes it applied in more and more field and replace traditional measurement using mechanical and electromagnetic method.
The approach, based on the principle of autocollimation theory, of constructing an two dimensional autocollimator with linear CCD as the photoelectricity transformer is presented in this article. Two methods are bringed forward to realize the measuring of two dimensional angle. One method is using single linear CCD and V shape reticule to achieve the aim. The other is using two linear CCD. At first, the design of relative software and hardware is detailed in this article, which includes the design of the driving circuit of linear CCD, the processing circuit of the output of linear CCD and its sequential circuit, data output interface circuit, initializing and setup circuit. Secondly, the design of frame grabbing circuit based on USB interface is presented, which includes the design of data input interface, frame grabbing contolling module and circuits related to USB interface. Thirdly, the design of relative software is presented, which includes the design of firmware running on USB chip and programs on host computer. At last, the debugging of software and hardware mentioned above and the result of measuring are briefly presented.
Key words : autocollimation, linear CCD, USB interface